Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
1991
Authors
Per Holm Nygaard Gunnar AbrahamsenAbstract
A study on the effects of eight years application of artificial acid rain on the vegetation and soil in an old Scots pine forest is described. Artificial rain of pH 2.5 and 3.0 caused severe damage to mosses, especially Pleurozium schreberi and Dicranum polysetum. The presence of Melampyrum pratense decreased drastically in plots treated with rain of pH 2.5 and 3.0. In Vaccinium myrtillus reduced leaf production was found in plots treated with rain of pH 2.5. A considerable decrease in base saturation had taken place in plots treated with pH 2.5 and pH 3.0 rain. Exchangeable calcium and magnesium in particular had been reduced, and the content of mangnesium in tissue of Vaccinium myrtillus appeared also to be reduced in plots treated with water of pH 2.5. The study demonstrates the need for better methods in evaluating vegetation responses in field studies. The use of visual cover recording should be supplemented by frequency analysis and harvesting methods to get better estimates of changes in vegetation structure.
Authors
Oddvar SkreAbstract
Support is given for the dark respiration as a limiting factor for growth at low temperatures. The existence of a so-called alternative respiration that is not linked to the growth process, supports this hypothesis, because of its possible function as a stabilizing factor (overflow function). Physiological mechanisms influencing plant survival in a cold environment and tree-line forming processes are discussed.
Authors
Gunnar Ogner Magne Opem Gabriele Remedios Gro Sjøtveit Britt SørlieAbstract
No abstract has been registered
Authors
Carl Gunnar Fossdal O. Nilssen B. Myhre B.H. LindqvistAbstract
No abstract has been registered
Authors
O. Marvik S. Rishovd Praveen Sharma Carl Gunnar Fossdal B.H. LindqvistAbstract
No abstract has been registered
Authors
Torild Wickstrøm W. Lund R. ByeAbstract
Selenium is determined in copper and nickel materials without any interferences. Hydrochloric acid plus hydrogen peroxide are used to dissolve the samples. The solution is then made alkaline with sodium hydroxide in order to eliminate the interference from copper and nickel by precipitation of the corresponding hydroxides. Sodium tetrahydroborate is added to the alkaline solution in order to reduce selenium(IV) to the selenide ion, and the solution is then filtered. The volatile selenium hydride is generated by acidification of the alkaline solution in a continuous flow system. The method was used successfully for the determination of selenium in three standard reference materials (SRMs) from the National Institute of Standards and Technology: SRM 398 Unalloyed Copper V, SRM 671 Nickel Oxide 1 and SRM 875 Cupro-Nickel, 10 (CDA 706) (doped). The detection limit of the method was approximately 1-mu-g g-1.
Authors
O. Nilssen Carl Gunnar Fossdal K. Eian B.H. LindqvistAbstract
No abstract has been registered
Authors
Bjørn Langerud Martin SandvikAbstract
No abstract has been registered
Authors
Bjørn Langerud Martin SandvikAbstract
No abstract has been registered
Authors
Mette Goul ThomsenAbstract
No abstract has been registered